High speed printer with improved paper engine arrangement



Dec. 3, 1968 J MORAN ET AL 3,414,106

HIGH SPEED PRINTER WITH IMPROVED PAPER ENGINE ARRANGEMENT Filed Oct. .1, 1965 5 Sheets-Sheet'l IN VENTOAS ROBERT J. MORAN HAROLD M. SHNEIDER EARL E. MASTERSON GALE J. BUNNER ATTORNEY Dec. 3, 1968 R. J. MORAN ET AL 3,414,106

HIGH SPEED PRINTER WITH IMPROVED PAPER ENGINE ARRANGEMENT Filed Oct. 21, 1965 3 Sheets-Sheet 2 g INVENI'OAS ROBERT J. MORAN HAROLD M. SHNEIDER' EARL E. MASTERSON GALE J. BUNNER Dec. 3, 1968 R. J. MORAN ET AL 3,414,106

HIGH SPEED PRINTER WITH IMPROVED PAPER ENGINE ARRANGEMENT Md Oct. 21, 1965 v 3 Sheets-Sheet a INVENTOAS ROBERT J. MORA HAROLD M NE R EARL E. MA RSON GALE J. BUNNER BY ATTORNEY United States Patent 3,414,106 HIGH SPEED PRINTER WITH IMPROVED PAPER ENGINE ARRANGEMENT Robert J. Moran, Littleton, Harold M. Shneider, Weston, Earl E. Masterson, Newtonville, and Gale J. Bunner, Randolph, Mass., assignors to Honeywell Inc., Minneapolis, Minn., a corporation of Delaware Filed Oct. 21, 1965, Ser. No. 499,909 1 Claim. (Cl. 197133) A high speed printer with a paper engine arrangement including a drive belt engaging pulleys on form-feed shafts, this arrangement characterized by a mounting of the drive motor, including its pulley, on a pivotable tensioning bracket in common with a tensioning pulley so that rotation of the bracket can, of itself, effect verticaltensioning of the Form engaged between these shafts; being also characterized by the mounting of the Format Code disc/ detector assembly on a second pi-votable bracket operatively adjacent one of the form-feed shafts and in common with a (selectively operable) brake for this shaft so that engagement of the brake and rotation of this bracket can effect a convenient formating adjustment without affecting the phase relation between these two; the arrangement also exhibiting a non-captive belt system with little or no back-bending inherent in it; together with a pulley-axle tilt adjustment means.

The present invention relates to improved high-speed printing apparatus especially as employed for data processing systems; and more particularly relates to improved paper advancing arrangements therein for advancing continuous paper forms, these arrangements being adapted for formating and tensioning adjustments and being characterized by a simplification of parts, and especially by an improved belt linkage arrangement wherein pulley belts are rendered non-captive and levelable without backbending thereof.

High-speed printers constitute valuable output devices for data processing systems today. However, in the course of performing the manifold and increasingly difiicult tasks required of them, such printers have become highly complicated. This is especially true of the paper engine portions thereof which are adapted to advance the continuous paper forms on which printing is to be effected. One reason is that paper engines are commonly adapted to also provide adjustments in tensioning and formating (i.e. print-line or Head-of-Form positioning) of the forms. Paper engines customarily comprise a prime mover, such as a motor and associated clutch and brake linkage, a timing belt drivingly coupling the prime mover to rotate drive pulleys which, in turn, synchronously rotate formadvancing means; the belt also being connected to other pulleys for paper-tensioning, for mating, belt-tensioning, and like functions. One major Weakness of such paper engines, however, is that the timing belt linkages are, at times, subject to wear, rupture or disengagement with the pulleys. The timing belts, therefore, must be inspected and adjusted periodically and constitute a weak link in the system. This down-time of a printer is usually expensive. Therefore, workers in the art recognize that it is highly advantageous to arrange a belt linkage to be readily accessible to service personnel and also to minimize the number of belts and the stresses imposed thereon so as to keep maintenance and replacement costs under control. The present invention is directed towards solving these problems by limiting the number of timing belts to a single belt connecting the prime mover directly to an associated pulley and by arranging the paper engine elements so as to keep the belt non-captive and thus accessible for convenient, uncomplicated maintenance and removal. The invention also provides an arrangement for 3,414,106 Patented Dec. 3, 1968 so locating the heavy drive motor commonly associated with timing belts as to pull the belt, rather than be pulled thereby, to avoid overstressing the belt (e.g. during paper tensioning). The invention further simplifies paper engines by minimizing the number of pulleys therefor, for instance, by arranging pulleys to perform multiple functions, such as paper-tensioning and belt-tensioning; papertensioning and motor-mounting, paper-advance and formating, etc.

Associated with the problem of timing belt wear is that of belt flexure whereby a timing belt, in the course of being diverted about a network of pulleys is commonly subjected to back-bending, or reverse-flexures. For instance, a belt section may be bent concavely about a first pulley and then bent oppositely (convexly) about one or more following pulleys, and in this manner incur one or more cycles of back-bending fiexures. Such backbending has been observed to quickly fatigue a belt leading to early rupture, though this problem has not been directly addressed by workers in the art heretofore. The present invention directs itself to minimizing back-bending, for instance prescribing a pulley arrangement that eliminates it entirely.

In the course of simplifying paper engine arrangements, the invention also prescribes a paper tensioning arrangement whereby the motor therefor is mounted directed on a tensioning pivot-bracket for stabilization of tensioning/driving linkage and for reduction of belt-stressing, as well as for compaction of the overall engine assembly, thus facilitating easy belt-removal.

Also associated with belt wear is the problem of pulley misalignment, where, for instance, a timing belt/pulley engagement may be such as to induce the belt to walk (that is, to move transverse to the pulling direction) because the belt is not aligned to meet the pulley in flat, uniform engagement. Such misalignment can cause a belt either to rub against the adjacent frame and quickly wear, or to slip off the pulleyinterrupting form-advancement in either case. The present invention provides a solution to belt-Walking problems by prescribing a pulley arrangement mounted to accommodate selective tilting of a pulley axis to selectively level the pulley with the engaging belt surface and thereby counteract belt-walk.

Paper-formating means are customarily provided in association with paper engines. However, heretofore, formating has been a rather inexact, cut-and-try affair. For instance, prior art high-speed printers commonly adjust for head-of-form by rotating the form-advancing spindles relative to a format code means to change the operational phases thereof relative one another. However, such an adjustment is necessarily inexact since it cannot be performed statically, that is, by referencing form position during adjustment; but, instead, requires the operator to guess at the proper degree of adjustment and then print a line or so to verify the results. Such a trial and error procedure almost always involves wasting a greater or less amount of paper length-something which is intolerable in many applications, for instance, where consecutively numbered forms are used (e.g. continuous strips of nunumbered checks). The present invention eliminates this waste of form length and provides a static formating capability according to a simplified formating arrangement. This arrangement employs a rotatable-bracket to mount the paper engine brake and the format code means together in constant phase relation, the bracket being simply rotated, with the brake engaged for static formating adjustments.

In summary, it will appear to those skilled in the art that the paper engine arrangement of the invention exhibits many highly desirable advantages never before combined in a high-speed printer; that is, paper engines according to the invention are new and advantageous in providing, in combination, the following desirable characteristics:

(l) A single belt linkage and a minimum number of associated pulleys (as few as 4);

(2) A belt-mounting arrangement that makes the belt non-captive and readily accessible (e.g. replace easily without tools), and, further, that can eliminate back-bending;

(3) Tiltable pulley means, adjustable to counteract belt- Walking;

(4) Drive motor means mounted directly upon a tensioning pivot-bracket for improved paper-tensioning action and for reduced belt stress; and

Rotatable format bracket means mounting braking and format code means together for static formating.

The foregoing advantages and novel features of the invention are provided in a preferred high-speed printer embodiment described below which is characterized by an improved form-advancing arrangement therein which comprises a pair of tractor pulleys, a tensioning bracket which is adjustably pivotable and which includes a pair of tensioning pulleys, one of which is coupled thereto via a mo t-or means, a format bracket which is selectively rotatable concentrically with one of said tractor pulleys to mount tractor braking means and formating code means in fixed phase relation; and an improved timing belt linkage connecting all of said pulleys. One of the aforementioned pulleys may be made selectively tiltable for different angular orientation thereof to counteract belt-walking. The foregoing and other characteristic features of novelty are pointed out with particularity in the claims annexed hereto and form a part of the present specification. For a better understanding of the invention, its advantages and specific objects attained with its use, reference should be had to the accompanying drawing and description wherein there is illustrated and described preferred embodiments of the invention.

Referring now to the drawing, wherein like reference numerals denote like parts:

FIGURE 1 is a perspective view of a preferred embodiment of the invention as employed for controlling the advancement of paper forms in a high-speed printer, providing form-tensioning and formating adjustments therefor;

FIGURE 2 is a schematic representation of a form-advancing arrangement similar to that of FIGURE 1, but greatly simplified and somewhat modified, for instance, to eliminate back-bending of the timing belt;

FIGURE 3 is a schematic side elevation of a tiltable pulley element of the arrangement in FIGURE 1;

FIGURE 4 is a side view, in partial section, of an alternate embodiment to that in FIGURE 3;

FIGURE 5 is similar to FIGURE 2, showing an advancing arrangement alternate thereto; and

FIGURE 6 is an exploded, perspective view of the formating-braking elements of FIGURE 1.

FIGURE 1 shows a preferred embodiment of the invention in the form of a form-advancing sub-assembly, or paper engine 1 of a high-speed printer apparatus such as employed to provide printed output for data processing systems. Functionally, this embodiment is an arrangement for synchronously rotating a pair of upper and lower tractor pulleys 15, 13 respectively, arranged to rotate a pair of associated upper and lower tractor spindles 15', 13 respectively. The form-engaging tractor means associated with spindles 15', 13 (not shown) are conventional, being arranged to engage continuous paper forms F (fragmentarily shown) for advancement past a rotatable, upwardly pivotable print drum PD in a known manner. As shown, print drum PD carries an associated character code disc CD and is upwardly pivotable, as shown by the paired arrows as, away from the plane of forms F for releasing engagement therewith and facilitating operator access to the forms. Print drum PD is thus rotatably and pivotably mounted in a sidewall portion 5 of the stationary printer frame. A resilient, toothed timing belt 7 is drivingly engaged with the teeth on tractor pulleys 13, 15 which, in

turn, are rotatably journaled in sidewall 5. Timing belt 7 is, itself, drivenly engaged by a motor pulley 23 which is mounted, in turn, on the drive shaft of a drive motor 21, the prime mover for paper engine 1, to be rotated thereby. Motor 21 may advantageously comprise a printed circuit motor and, as a feature of the invention, is fixedly mounted upon a tensioning bracket 25, being directly coupled to pulley 23. Tensioning bracket 25 is pivotably journaled in a sidewall 5 at bearing 26 and is threadably or otherwise engaged, through flange section 127, with a tensioning shaft, or lead screw 28. Screw 28 is rotatably journaled (e.g. with indicated collar fitting 5-0) from sidewall 5 for conventional screw-translation with respect thereto and includes a manual tensioning knob 121. Thus, manual rotation of knob 121 is adapted to screwingly thrust bracket 25 with respect to wall 5 to pivot it a selected amount about bearing 26 for vertical paper tensioning, being pivotable either clockwise or counter-clockwise, as desired. Tensioning bracket 25 also carries a tensioning pulley 27 rotatably journaled therein and also arranged to be laterally adjustable along mounting slot SL therein (shown in phantom) for tensioning of belt 7. While any conventional means may adjustably fix pulley 27 along slit SL, one means comprises a captive nut held in raceways (indentations) along the slot edges to be freely slideable therealong and also be frictionally held therealong when tightened onto threads on the pulley shaft. Tensioning pulley 27 is adapted to engage the smooth (untoothed) side of timing belt 7 to perform the triple functions of: diverting belt 7 about the projecting portions of print drum PD; providing a form-tensioning pulley when tensioning bracket 25 is rotated (as described below); and providing a tension adjust for belt 7, according to its position along slot SL. Thus, in sum, paper engine 1 includes a paper-tensioning arrangement 2 comprising a tensioning pivot-bracket 25 mounting tensioning pulley 27 and motor 21, together with rotation-controlling lead screw 28 and its associated elements, motor 21 being coupled to belt 7 via drive pulley 23. It will be apparent to those skilled in the art that this arrangement for mounting a paper engine drive motor means directly upon a tensioning pivot-bracket will provide improved paper tensioning action such as by stabilizing and counter-balancing the tensioning bracket, by reducing belt loading and stress during tensioning, and the like. More particularly, consideration of FIGURE 1 (see also FIGURE 2 for an alternate embodiment) will reveal that when knob 121 is rotated manually and lead screw 28 caused to screwingly thrust bracket 25 either clockwise or counter-clockwise pulleys 23, 27 will be translated unidirectionally relative one another to transversely divert belt 7 oppositely by relatively equal compensatory amounts (D, +D), without significantly changing belt tension. For example, pulley 23 may transversely thrust one section of belt 7 while pulley 27 releases the other opposite section a relatively equal amount, to thereby rotate one of the form advancing spindles 15, 13 relative to the other, thereby either stretching or relaxing the length of form F therebetween. The mounting of the prime mover (motor 21) below the center of gravity of bracket 25 helps to stabilize and balance it, while coupling the motor directly to pulley 23 will be seen to advantageously utilize the rather considerable motor mass to pull timing belt 7, rather than forcing belt 7 to pull the motor load and consequently overstressing it. Expressed otherwise, when bracket 25 is rotated, formating pulleys 23, 27 will be shifted rather markedly (and oppositely) in their respective spacing from spindle pulley 13 (i.e., relatively radially-shifted), while remaining at relatively the same respective distances from spindle pulley 15 (i.e., relatively circumferentially-shifted). As a result, the intermediate section of belt 7 that wraps pulleys 13 will be shifted and thus will rotate 13; while the other intermediate belt section about pulley 15 will stay relatively unshifted.

Alternate paper tensioning arrangements 2' in FIGURE 2 (see below) and 2" in FIGURE 5 are, in most respects, similar to that shown in FIGURE 1. Tensioning assembly 2" coacts with a timing belt 7" so as to change the relative phase between a pair of form-advancing spindles (not shown) and an associated pair of upper and lower drive pulleys 13", respectively; thus, phasing the two spindle shafts without significantly affecting the tension of the flexible belt member coupling them. For this, tensioning arrangement 2 includes a right-hand-threaded lead screw 48 coupled to a left-hand-threaded lead screw 49 by a coupling 43 to provide for initial tensioning of timing belt 7". Coupling 43 is pinned to lead screw 48 and releasably secured to lead screw 49 by a lock-nut 47 to provide this adjustable dis-placement when a mounting shaft therefor is rotated by a manual knob '21". Once the desired displacement and belt-tension is achieved, the left-hand-threaded lead screw 49 is secured by locknut 47. A top carrier block 270 is threadably engaged by right-hand screw 48, while a bottom carrier block 230 is likewise engaged by left-hand screw 49. A lower tensioning pulley 23" is mounted on block 230 while an upper (idler) pulley 27" is mounted on block 270. A guide bar 41 is slidably engaged in bores in blocks 230, 270 for assuring a smooth, stable, non-rotatable sliding displacement therebetween. Bar 41 is fixedly mounted between the ends of a stationary mounting bracket, or yoke, 5", afiixed to a stationary portion of the printer frame. Yoke 5" fixes the positions of lead screws 48, 49 and journals them.

In operation, it will be seen that, if one initially releases lock-nut 47 to enable carrier block 230 on the lefthand screw 49 to move independently of the right-hand screw 48 and its associated carrier block 270, one may simplify belt replacement and provide the necessary adjustments for initial belt tension. Once the desired displacement and belt tension is provided, lock-nut 47 is secured and the two screws 48, 49 perform as a single unit. For form-tensioning (i.e. phasing of pulleys 15", 13") a knob 21" On right-hand lead screw 48 is rotated to displace pulley 23" from pulley 27", rectilinearly driving them in opposite directions due to the coupled lefthand and right-hand-threaded screws. As a result the distance from idler 27" to lower tractor pulley 13" will decrease by the same amount as the distance from pulley 13" to tension wheel 23" increases. This will cause pulley 13 to revolve and to phase its associated spindle without affecting upper tractor pulley 15" and its associated spindle. Hence, the overall timing belt length is maintained constant (providing constant belt tension) during phasing by moving one spindle pulley relatively independent of the other with the described simple, readily obtainable parts, arranged to flex belt 7 equally and oppositely. That is, pulling pulley 27" toward pulley 13" can be assumed to release a given length (D') of belt 7 to allow pulley 13" to rotate a prescribed amount; while this system simultaneously thrusts pulley 23" away from pulley 13 to take up about the same belt length (+D) and consequently allow the same amount of rotation. By contrast, where these formating pulleys are displaced relative to (conjunctively toward and away from) spindlepulley 13", they are kept substantially the same respective distances from the other spindle-pulley 15", being arranged to move along (or close to) respective radii about pulley 15namely: r-27 and r-23".

Similarly, with the embodiment of FIGURE 1, formating pulleys 23, 27 will be recognized as arranged to be markedly displaced with respect to (toward and away from) one spindle pulley (13), while being kept at relatively the same respective distances from the other spindle pulley (15). It will be noted that this design provides that lower lengths 71, 73 of belt 7 are kept parallel and at center position as well as perpendicular to complementary upper belt-lengths 75, 77. However, a small differential may result since lengths 75, 77 do not describe 6 exactly the same arc, though this is of no practical consequence.

Paper engine 1 also includes a formating arrangement 3 as best seen in FIGURES 1 and 6, which includes a rotatable format bracket 31 rotatably journaled in sidewall 5 to be concentric with tractor pulley 15 and the associated spindle 15'. Format bracket 31 is arranged to be selectively rotatable by a worm-geared shaft 36 when an associated formating knob 33 thereon is rotated manually. Thus, shaft 36 drivingly engages a gear sector portion 34 of format bracket 31. It is a feature of the invention that format bracket 31 carries a spindle-locking means, or hold-brake 35, fixedly coupled on a collar portion 31C thereof extending through sidewall 5. Bracket 31 also carries an indexing or format code means, a mounting portion of which is indicated schematically in phantom at F CA (the formating tape, etc., being omitted for clarity). Such indexing means conventionally indicates paper web position (tractor phase) e.g., to brake 35. Brake means 35 is adapted to be selectively coupled to hold upper spindle 15' stationary with respect to itself, to bracket 31, to mount FCA, etc., and may comprise any well-known brake means adapted for this purpose. Format mount FCA is afiixed on bracket 31 on the side thereof opposite brake 35 and is thus arranged in constant phase-relation therewith. Mount FCA, FCAB is simply a well-known type of support for a photodetector assembly, or its equivalent, used to generate Well-known format-code signals. Thus, it will be apparent that when worm-shaft 36 rotates formating bracket 31 the brake 35 and format mount FCA will together be rotated therewith in unison without any change in their relative operating phases. A diverter pulley 11 may also be provided to divert belt 7 about format mount FCA, though it may be otherwise be omitted (see FIGURE 2).

According to another feature of the invention (described below) one of the pulleys, such as pulley 11, may be arranged to counteract any walking of timing belt 7, that is movements thereof along the direction of the pulley axis and transverse to its driving direction. This is best indicated in FIGURE 3, or alternatively in FIGURE 4, and is described below. It Will be seen that the above formating arrangement according to the invention provides a format-bracket for mounting brake means and format code means coupled together for static formating. The operation of formating arrangement 3 will be apparent to those skilled in the art from the above description but may be summarized as follows. When formating knob 33 rotates shaft 36 to pivot bracket 31 with brake 35 engaged on spindle 15, paper form F will be advanced by prescribed increments while being aligned statically, for instance, being checked for registry with a guide-line (of any well-known type) indicating head-of-form between advance increments by the operator. The rotation of brake 35 will, of course, carry bracket 31 and formating code mount FCA thereon around with it, an identical angular mount maintaining their relative operating phase constant and without changing the tension in belt 7. Thus, static formating may be performed and no form length need be wasted for verification of formating adjustments as with prior art arrangements.

The operation of the overall novel paper engine 1 in the embodiment of FIGURE 1, including formating and tensioning assemblies 3, 2 respectively, will be apparent to those skilled in the art from the above description. For instance, it will be apparent that the number of timing belts and associated pulleys has been reduced and that the belt has been rendered non-captive, being arranged so that no element spans a belt section. This is understood better relative to the following description of the alternate paper engine arrangement in FIGURE 2. FIGURE 2 indicates, very schematically, a type of paper engine arrangement 1 which is roughly the same as provided in the embodiment of FIGURE 1, being somewhat modified and simplified, however. Thus, paper engine 1' comprises a pair of upper and lower tractor pulleys 115, 113, respectively, engaged by -a timing belt 7 together with a modified paper tensioning arrangement 2. Tensioning subassembly 2 will be seen to comprise a tensioning bracket 25 pivotably journaled in sidewall 5 by bearing 26 to be pivoted either clockwise or counter-clockwise by a lead screw arrangement 121. Tension bracket 25' carries a tension pulley 27 adjustably and rotatably mounted therefrom, being adjustably positionable along slot SL therein for adjusting belt tension as with like pulley 27. Bracket 25' also carries a drive motor 21 fixedly mounted thereon and having its rotating shaft directly coupled to a drive pulley 23' adapted to drive timing belt 7 after the manner of pulley 23.

It will be observed that, according to a feature of the invention, paper engine 1 eliminates back-bending of timing belt 7 by providing a pulley arrangement which diverts a belt in substantially only one sense, i.e. which has only unidirectional belt-bends about the pulleys, all bends being inward or re-entrant toward the interior of the belt periphery, thus eliminating all back-bending to greatly enhance belt life. Such inward flexures are to be contrasted with the inw-ard/ outward fiexures such as about pulley 27 (FIGURE 1). It has been observed that the inward/ outward flexing of timing belts resulting from inclusion of one or more pulleys arranged to bend them outwardly quickly fatigues them, leading to their early rupture, especially along tooth-indentations. Paper engine 1 will be seen to avoid this wear by arranging the pulleys thereof (i.e. pulleys 113, 115, 27, 23) to divert belt 7 uniformly inwardly, according to the invention. Paper engine 1 in FIGURE 1 is similar having all inward (or convex) belt bends, except for that about diverting tensioning pulley 27 which is required simply to divert belt 7 about pivotable print drum PD. Thus, the invention provides an arrangement of paper engine pulleys relieving back-bending stresses of belts therefor. Besides this reduction of backbending, it will be noted below that other forms of lateral belt-stressing are eliminated by the invention, such as the stresses resultant from belt/ pulley misalignment relieved by a novel tiltable pulley arrangement described below with reference to FIGURES 3 and 4.

According to another feature of the invention, it will be apparent to those skilled in the art that paper engine 1 and alternate engine 1' provide a more accessible noncaptive timing belt by arranging pulleys etc., so that the belt is never trapped behind or between spanning, overlying elements which would need to be removed before the belt could be removed or inspected. Of course, contributing to this accessibility is the mounting of the drive motor (21 or 21) from the tensioning bracket (25 or 25) to compact the overall paper engine; plus the mounting of format code mount FCA on bracket 31 to be within the confines of belt 7. Arranging the engine to require no more than a single timing belt, coupling the motor (21 or 21) and assoicated spindle pulleys (113, 115 or 13, 15) and other simplifying features, which reduce the number of pulleys and force parts to perform multiple functions, also improve accessibility.

Belt walking is counteracted according to another feature of the invention which provides a tiltable axle, pulley-leveling arrangement, such as shown in FIGURE 4. Here, a belt-receiving pulley 11' (which may be smooth, toothed etc.) is rotatably journaled on an axle 12 mounted from a block portion 91 of a tilt-mounting 90 to project obliquely from Wall 5 along tilt-axis AL. Axis AL diverges from normal axis N, the normal to wall 5, by a prescribed angle C. In this way, pulley axle 12 for diverting pulley 11' (FIGURE 4) is made tiltable, being mounted on tilt-mounting 90 to be selectively oriented to counteract this belt walking. Axle 12 is press-fit into a sleeve 99 (in phantom) housed in a bore in tilt-block 91 and is arranged to be selectively tilted in any direction about normal axis N as indicated by arrow b, and in various tilt-degrees as indicated by arrow a. Block 91 is releasably mounted on wall 5 to be selectively pivotable about an eccentrically located pivot axle 95 so that, when pivot 95 is released, block 91 may be pivoted about the normal axis N (indicated by arrow b) to thereby vary the direction of tilt for axle 12 from normal axis N. A conventional lock-washer arrangement 96 provided on the opposite side of sidewall 5 releases axle 95 so that block 91 and pulley 11 may be swung about normal axis N to a prescribed direction where it will counteract a given tendency of belt 7 to walk (in N direction) across pulley 11 and other associated pulleys. For instance, if belt 7 were walking inwardly toward sidewall 5, this would suggest that the inward side of pulley 11 were somewhat low, indicating that axle 12' should be tilted to project somewhat more downwardly below normal axis N to counteract this. Axis N is equivalent to the normal to the driving pulley plane defined by the belt 7 as looped over its associated pulleys. (See FIGURE 1).

Besides accommodating selectable changes in the direction of tilt (i.e. orientation of axis AL relative to normal axis N), tilt mounting also allows selectable adjustment of the degree of tilt, i.e. of the magnitude of divergence angle C, according to the invention. To effect this, block 91 is made adjustably compressible asymmetrically, such as by providing diagonal cut-out 92 therein and distorting means such as take-up screw 93 or equivalent means to controllably close them outh of cut-out 92 and thereby tilt pulley 11' on the surface of block 91 as indicated by arrow a. A return screw may be added to oppose the thrust of tightening screw 93 and selectably thrust pulley 11' oppositely if block 91 is not sufficiently resilient.

Of course, equivalent means may be provided; for in stance, axle 12 may be mounted orthogonally in block 91 and journaled rotatable therein, being aifixed to pulley 11' and other equivalent means provided to tilt the axlereceiving portion of block 91.

An alternate tilting arrangement 60 is shown in FIG- URE 3 which, like the tilt-mount 90 in FIGURE 4, provides selectable adjustment of tilt direction and degree (divergence angle). As before, a pulley-bearing assembly 11" is mounted on a pulley shaft 68, removably coupled to tilt mounting 60, a stud portion of which 64 is threadably engaged in a tapped bore 51 in sidewall 5. Stud 64 includes an enlarged head 65 with a top annular bore 66 cut therein to have the longitudinal axis thereof SS diverge a prescribed angle d from the longitudinal axis of stud 64 and normal axis NN, the normal to sidewall 5. Bore 66 is adapted to receive a resilient sleeve, or ring, 67 which is centrally bored to be press fit onto extended shaft portion 68 of pulley shaft 68, as shown. This central bore in ring 67 is formed to deviate from the longitudinal ring axis and stud-bore axis SS by divergence angle at or an equivalent amount. A set screw 62 is provided to fix the rotational position of sleeve 67 and bearing shaft 68 in bore 66, while a jam nut 63 similarly fixes the rotational and longitudinal position of stud 64 in wall 5. It will be evident that stud 64 may be rotated to orient it with the belt path (fixing tilt direction and coarse tiltdegree) and then locked into this orientation with jam nut 63, head 65 preferably being spaced about one thread clearance from wall 5. Then sleeve-pulley assembly 67/68 may be rotated in bore 66 for fine tilt-degree adjustment (so that belt 7 tracks) being secured thereat by set screw 62. Thus, if the axis of bore 66 diverges about 3, for instance, from normal axis NN, and the annular bore in sleeve 67 diverges 3 from the longitudinal axis of sleeve 67, the tilt angle may be varied in amount from about 0 to about 6 (cancellation and reinforcement of these divergence angles); while tilt direction may also be varied.

What is claimed is: v

1. In a paper feeding arrangement for a high-speed printer including a stationary rinter frame, upper and lower paper feed means mounted on said stationary printer frame for advancing a web of paper forms past a print station, and upper :and lower tractor pulleys respectively connected to said upper and lower paper feed means, an improved paper tensioning arrangement in combination therewith comprising: a supportmeans; journal means pi-votally mounting said support means on said stationary printer frame between said upper and lower tractor pulleys; drive motor means mounted on said support means below said journal means and having a drive pulley connected thereto; a tension pulley rotatably mounted on said support means above said journal means, said tension pulley being adjustable radially relative to said journal means; an endless flexible timing belt means coupling said upper and lower tractor pulleys, drive pulley and tension pulley; and manually operable means mounted on said stationary printer frame and operable to pivot said support means about said'journal means; the arrangement being such that pivoting of said support means together with said drive motor means, drive pulley and tension pulley disposed thereon about said journal means effectively rotates one of said upper and lower tractor pulleys relative to the other of said up 10 per and lower tractor pulleys through said timing belt means, thereby to tension said web in said. high-speed printer by varying the relative phase between; said upper and lower paper feed means without significantly affecting the tension along said timing belt means.

References Cited UNITED STATES PATENTS 1,218,686 3/1917 Morse 74228 X 2,349,084 5/1944 Findley.

2,368,848 2/1945 Krueger 74 242.15 X 2,601,431 6/1952 Christie 74242.15 X 2,983,355 5/1961 Iaparell 197-33 3,049,276 8/1962 Wilkins 226111 X 3,136,466 6/1964 Antonucci 74242.8 X 3,147,900 9/1964 Konkel 226--111 3,166,947 1/1965 'Hende-rshot 74216.5 3,288,264 11/1966 Gabrielson et a1. 197--133 ROBERT E. PULFRE-Y, Primary Examiner.

E. T. WRIGHT, Assistant Examiner. 

1. IN A PAPER FEEDING ARRANGEMENT FOR A HIGH-SPEED PRINTER INCLUDING A STATIONARY PRINTER FRAME, UPPER AND LOWER PAPER FEED MEANS MOUNTED ON SAID STATIONARY PRINTER FRAME FOR ADVANCING A WEB OF PAPER FORMS PAST A PRINT STATION, AND UPPER AND LOWER TRACTOR PULLEYS RESPECTIVELY CONNECTED TO SAID UPPER AND LOWER PAPER FEED MEANS, AN IMPROVED PAPER TENSIONING ARRANGEMENT IN COMBINATION THEREWITH COMPRISING: A SUPPORT MEANS; JOURNAL MEANS PIVOTALLY MOUNTING SAID SUPPORT MEANS ON SAID STATIONARY PRINTER FRAME BETWEEN SAID UPPER AND LOWER TRACTOR PULLEYS; DRIVE MOTOR MEANS MOUNTED ON SAID SUPPORT MEANS BELOW SAID JOURNAL MEANS AND HAVING A DRIVE PULLEY CONNECTED THERETO; A TENSION PULLEY ROTATABLY MOUNTED ON SAID SUPPORT MEANS ABOVE SAID JOURNAL MEANS, SAID TENSION PULLEY BEING ADJUSTABDLE RADIALLY RELATIVE TO SAID JOURNAL MEANS; AN ENDLESS FLEXIBLE TIMING BELT MEANS COUPLING SAID UPPER AND LOWER TRACTOR PULLEYS, DRIVE PULLEY AND TENSION PULLEY; AND MANUALLY OPERABLE MEANS MOUNTED ON SAID STATIONARY PRINTER FRAME AND OPERABLE TO PIVOT SAID SUPPORT MEANS ABOUT SAID JOURNAL MEANS; THE ARRANGEMENT BEING SUCH THAT PIVOTING OF SAID SUPPORT MEANS TOGETHER WITH SAID DRIVE MOTOR MEANS, DRIVE PULLEY AND TENSION PULLEY DISPOSED THEREON ABOUT SAID JOURNAL MEANS EFFECTIVELY ROTATES ONE OF SAID UPPER AND LOWER TRACTOR PULLEYS RELATIVE TO THE OTHER OF SAID UPPER AND LOWER TRACTOR PULLEYS THROUGH SAID TIMING BELT MEANS, THEREBY TO TENSION SAID EB IN SAID HIGH-SPEED PRINTER BY VARYING THE RELATIVE PHASE BETWEEN SAID UPPER AND LOWER PAPER FEED MEANS WITHOUT SIGNIFICANTLY AFFECTING THE TENSION ALONG SAID TIMING BELT MEANS. 